Here's some commentary from The Atlantic on the issue of why Wall Street primarily seems to hire Ivy graduates.
What does that have to do with the undergraduate application process? Well, I think it has something to do with why kids want the most highly selective/big name schools. They perceive advantages that are economic and prestigious. As the piece points out, there are just as bright kids in other schools, but it's easier to recruit from a handful of places, rather than having to travel all over the country looking for those who might make the cut.
It's all crazy. But it is also how the game is played, at least now. So how should we advise our teens when increasingly the ability to make a living plays into decisions our teenagers have to make about colleges?